Conventional single reel cartridges for recording tape comprise a flattened, generally square box-like shell with a single supply reel of recording tape centrally located in the shell. The length of recording tape is attached at one end to the supply reel and the other end is a free end which is attached to a leader block. The leader block is drawn from the cartridge by a tape drive threader which moves the tape through an elongated tape path in the drive, past tape bearings and guides, a tape read/write head, more tape bearings and guides, and to a take up reel.
Typically, the tape winds onto reels in a non-uniform profile which results in lateral tape motion at the head and tape guides when the tape is unwound at typical tape speeds. Thus, tape bearings and guides are required to insure that the tape is stable when it passes the head in order to meet design requirements for data density and performance.
It is desirable to provide high capacity and high performance tape drives. One means of increasing capacity is to reduce the thickness of the recording tape to permit a greater length of tape to be stored in a tape cartridge, but this leads to increased susceptibility to vibration and decreased stability of the tape, and requires a more stable tape path. As described in U.S. Pat. No. 5,155,639, Platter et al., care must be taken to develop a proper tape path between the supply and take up reels, and across the tape read/write head, to assure proper registration of the tape with the tape head. As the result, conventional tape paths are long and cumbersome and expensive. It is also desirable to reduce the size of the tape drive while retaining stability of the tape. The '639 patent reduced the size of the tape drive to an 8 inch form factor by employing an improved tape threading mechanism and an improved take up reel in the drive.
It is also desirable to provide such tape drives in even smaller form factors. To do so, requires a smaller tape path.